Continuous flow gas turbine



Feb. 10, 1942. R. LEDUC CONTINUOUS FLOW GAS TURBINE Filed Dec. 25, 1938[Mam r01? B L ecizzc Patented Feb. 10, 1942 UNITED STATES PATENT OFFICE.f;

' 1 l l I 2,272,676 f ooN'riN ous FLow GAS TURBINE,

Ren Leduc, Le Vesinet, France Application December 23,1938, SerialNo.247,499 iolaim. (c1. co -4 I I. The object of my invention is to providecertain improvements incontinuous flow gas tursame rotor.

I'have found ditions of efficiency if special arrangements are not used.On the other hand, I have also found that detonations occur at highspeeds and that it is impossible to obtain a flame which is sufficientlyshort to be contained entirely inside the rotor.

According to my invention, I form the turbine by combining a series ofcompression nozzle radially arranged on a rotor, and a series ofexpansion nozzles formed by radial blades arranged at the periphery ofthe same rotor, with an annular combustion chamber which is interposedbetween these two series of blades and in which the juxtaposed flames ofthe burners form a substantially continuous ignition ring. The shapesand dimensions of the compression nozzles and of the combustion chamberand the speeds of the gaseous fluids are as far as possible chosen insuch a manner that the flames are directed very obliquely and do notextend outside the rotor.

The combustion chamber is formed by a space which is limited on the onehand by the outlet of the compression nozzles and the inlet of theexpansion nozzles, which form parts of the rotor, and on the other handby at least one fixed wall which is secured for example to the outercase. Under these conditions, the gaseous current is involved inconsiderable turbulence in the com- I bustion chamber, although thegaseous fluid participates in the circular movement of the rotor. I

The turbulence is further increased by the fact that said turbinerotates at extremely 'high speeds, preferably exceeding 10,000 R. P. M.,and that the friction of the air at high speed against the abovementioned fixed wall causes a considerable increase of the temperatureof the boundary layer, thereby considerably increasing the speed ofpropagation of the flame.

Furthermore and in order to still further increase the turbulence, Idistribute the burners at the periphery of the turbine, at a shortdistance from each other, so that their flames are substantially incontact .with each other and the fuel burns in a kind of ring of fire.

By way of exampleand in order to facilitate the comprehension of theensuing description, an

that the supply of heat to n oz-H zles which. are arranged side by sideon ,the periphery of a wheel is effected under poor.con-- cry of therotor.

embodiment of theinventi'on hasbeenshown in the accompanying drawing inwhich: Figure 1 shows a longitudinal section of a turbine according tothe invention.

Figure 2 shows a section along the line II II -ofFigure1..

Figure 3 shows the development periph- Figure 4 shows a partialdiagrammatical' view in section along the line IV -IV ofFigure '1.

In the example shown in Figures 1, 2 and 3, the turbine comprises arotor provided with radially juxtaposed nozzles forming an arrangementwhich is divided into a compression zone I, a combustion chamber 2 andan expansion zone 3.

The compression zone I is formed by the two discs 6 and 9 between whichare arranged blades l 0 (Figure 3) which form radial partitions whichlimit divergent radial nozzles.

This arrangement provides, inter alia, the advantage of balancing thethrusts so that the resultants of same on the main shaft issubstantially nil. The inlet to the compression zone is preferablyformed by means of an inlet helix I which is intended to eliminatesudden changes of direction in this part of the apparatus.

The second disc 6 of the rotor carries at its periphery expansion blades3 which are free at their outer ends since at the extremely high speedin question outer bracing members would not withstand the stressesdeveloped and because it is not necessary to obtain a perfectfluid-tightness at this point. 4

The combustion chamber 2 is formed by the space which is limited on theone hand by the fixed wall 4, and on the other hand by the outlet 8 ofthe compression nozzles and the inlet of the expansion nozzles 3. Saidcombustion chamber is therefore of annular shape.

All the way around, and preferably in the fixed wall 4, are arrangedburners 5 which inject the liquid fuel into the combustion chamber. Saidburners, in the example shown in the drawing, open into the front partof said chamber, so that the flame has sufllcient space to extendwithout exceeding the limits of the rotor.

Owing to the speed of rotation and the eifect of the fixed wall, theflame of the burners takes up an oblique position with respect to theaxis.

In Figure 3, it will be seen that combustion should take place over alength V if the gases were not in contact with the fixed wall 4. As theyare in contact with the wall I, the general flow takes place along theresultant of the speed inside the nozzles v and of the peripheral speedu and the fiame can therefore be of the length while remaining insidethe rotor.

It will also be seen in Figure 3 that the various flames touch eachother, owing to the empty space outside the terminal edge 8 of theblades of the rotor; a considerable continuity of combustion is thusobtained, so that there is no detonation and consequently the efiiciencyis increased.

A fluid-tight device is provided at the front part of the combustionchamber, between the.

fixed wall and theadjacent movable part. In the example shown in thedrawing, the outer part of the front disc 9, which extends slightlybeyond the edges 8 of the compression blades, penetrates into an annulargroove or channel ll provided in the front part of the fixed wall.

On the other hand, it is not necessary to provide a fluid-tight devicebetween the expansion blades 3 and the fixed part and said blades openfreely at their periphery.

When the fiuid leaves the expansion blades it still has quite a highspeed. This fluid passes into the annular pipe I! which is coaxial withthe shaft of the turbine and slightly divergent.

Under these conditions the speed upon leaving the pipe I2 is less thanat the entrance and consequently the energy recovered is added to thepower obtained by the expansion blades 3. The efilciency of the assemblyis thereby increased.

I claim:

A gas turbine comprising a shaft, 9, pair of spaced elements mountedupon said shaft, walls extending between said elements located in planesextending through the longitudinal axis of said shaft to form divergentmovable compression nozzles, one of said elements having an openingtherein located adjacent said shaft to form with said walls entranceorifices for said compression nozzles located nearer said shaft than theexit orifices of said compression nozzles, a single stage of expansionblades mounted upon the peripheral portion of the other of saidelements, a fixed wall concentric with said shalt cooperating with saidblades to form expansion nozzles, said fixed wall extending over theexit orifices of said compression nozzles to form a combustion chamberlocated between said exit orifices of said compression nozzles and theentrance orifices of said expansion nozzles, burners located in saidcombustion chamber and means for leading fuel to said burners, saidfixed wall being provided with an annular groove and said element whichhas an opening therein having its peripheral portion extending into saidgroove.

RENE LEDUC.

